Latest news with #polarregions
RNZ News
5 days ago
- Health
- RNZ News
Earth's seasonal rhythms are changing, putting species and ecosystems at risk
By Daniel Hernández Carrasco and Jonathan Tonkin of Monsoon rains represent one of Earth's major seasonal cycles. Photo: Shutterstock Seasonality shapes much of life on Earth. Most species, including humans, have synchronised their own rhythms with those of Earth's seasons. Plant growth cycles, the migration of billions of animals and even aspects of human culture - from harvest rituals to Japanese cherry blossom viewings - are dictated by these dominant rhythms. However, climate change and many other human impacts are altering Earth's cycles. While humans can adapt their behaviour by shifting the timing of crop harvests or indigenous fire-burning practices, species are less able to adapt through evolution or range shifts. Our new research highlights how the impacts of shifting seasons can cascade through ecosystems, with widespread repercussions that may be greater than previously thought. This puts species and ecosystems at risk the world over. We are still far from having a full picture of what changes in seasonality mean for the future of biodiversity. From tropical forests to polar ice caps and abyssal depths, the annual journey of Earth around the Sun brings distinct seasons to all corners of the planet. These seasonal rhythms shape ecosystems everywhere, whether through monsoonal rains in equatorial regions or the predictable melt of snowpack in mountain ranges, but the seasonality of these processes is changing rapidly, due to local human impacts. This includes dams in many rivers, which completely and abruptly disrupt their natural flow, and deforestation, which changes the timing of the onset of the rain season. These local influences are compounded by climate change, which is systematically modifying seasonal patterns in snow cover, temperature and rainfall around the world. From the earlier seasonal melting of glaciers and the snowpack to the disruption of monsoonal rain cycles, the effects of these changes are being felt widely. Many important ecological processes we rely on could be affected. A mismatch between plankton blooms and the life cycles of fish could affect the health of fisheries. Tourism dependent on seasonal migrations of large mammals could suffer. Even the regulation of the climate system itself is tightly controlled by seasonal processes. Changing seasonality threatens to destabilise key ecological processes and human society. The seasonal rhythms of ecosystems are obvious to any observer. The natural timing of annual flowers and deciduous trees - tuned to match seasonal variations in rainfall, temperature and solar radiation - transforms the colours of whole landscapes throughout the year. The arrival and departure of migratory birds, the life cycle of insects and amphibians, and the mating rituals of large mammals can completely change the soundscapes with the seasons. These examples illustrate how seasonality acts as a strong evolutionary force that has shaped the life cycles and behaviour of most species, but in the face of unprecedented changes to Earth's natural rhythms, these adaptations can lead to complex negative impacts. For instance, snowshoe hares change coat colour between winter and summer to blend in with their surroundings and hide from predators. They are struggling to adapt to shifts in the timing of the first snow and snowmelt. The impact of changing seasonality on hare populations is linked with changes in predation rates, but predators themselves may also be out of sync with the new onset of seasons. Our research highlights that these kinds of complex interactions can propagate impacts through ecosystems, linking individual species' seasonal adaptations to broader food web dynamics, or even ecosystem functions such as carbon sequestration. Although biologists have studied seasonal processes for centuries, we know surprisingly little about how they mediate any ecological impacts of altered seasonality. Our findings show we are likely underestimating these impacts. The distinct mechanisms involved deserve further attention. Until we account for these complex processes, we risk overlooking important ecological and human consequences. Understanding the extent to which impacts of altered seasonality can interact and propagate from individuals to whole ecosystems is a big challenge. It will require different types of research, complex mathematical modelling and the design of new experiments, but it is not easy to manipulate the seasons in an experiment. Scientists have come up with inventive ways of experimentally testing the effects of altered seasonality. This includes manually removing snow early in spring, manipulating rainfall patterns through irrigation, and moving plants and animals to places with different seasonality. Some researchers have even recovered seeds from centuries-old collections to sprout them and look at how recent changes in climate have affected plant populations. These efforts will be of great value for forecasting impacts, and designing effective management strategies beneficial for ecosystems and humans alike. Such efforts help to anticipate future shocks and prioritise interventions. For instance, understanding the mechanisms that allow native and non-native species to anticipate seasonal changes has proven useful for "tricking" non-native plants into sprouting only in the wrong season. This gives an advantage to native plants. Similarly, studies on the molecular mechanisms involved in the response to seasonality can help us determine whether certain species are likely to adapt to further changes in seasonal patterns. This research can also point out genes that could be targeted for improving the resilience and productivity of crops. Not only are we likely underestimating the ecological risks of shifting seasons, we tend to forget how much our everyday lives depend on them. As Earth's rhythms change, the risks multiply, but so does our opportunity to better understand, anticipate and adapt to these changes. This story was originally published on [ The Conversation]. Daniel Hernández Carrasco is a PhD candidate in Ecology at University of Canterbury. Jonathan Tonkin is associate professor of Ecology and Rutherford Discovery Fellow at University of Canterbury
The Guardian
6 days ago
- General
- The Guardian
Birds were nesting in the Arctic during age of dinosaurs, scientists discover
The Arctic might evoke images of polar bears and seals, but 73m years ago it was a dinosaur stomping ground. Now fossil hunters say these beasts shared their turf with a host of different birds. Researchers believe their discovery of more than 50 bird fossils from the Prince Creek formation in Alaska is the oldest evidence of birds nesting in polar regions, pushing back the date by more than 25m years. 'The previous oldest evidence for polar nesting is a penguin colony from the Eocene of Antarctica [that lived about 46.5m years ago],' said Lauren Wilson, first author of the work from Princeton University. More than 200 species of bird nest in the Arctic today, with the researchers saying they are crucial members of the ecosystem, helping with essential tasks such as pollination and seed dispersal. And the latest findings suggest their presence is nothing new. 'These new fossils fill a major gap in our understanding of bird evolution,' said Prof Patrick Druckenmiller, director of the University of Alaska Museum of the North and a co-author of the study published in the journal Science. While the earliest birds emerged in the Late Jurassic, about 150m years ago, the delicate nature of bird bones means such animals are rare in the fossil record. 'Prior to this work, and with the exception of a few footprints, bird fossils weren't known from Alaska,' said Druckenmiller. The discovery involved far more than mere good fortune, with the team carefully excavating bones as well as washing and sieving material from small, sandy deposits to isolate tiny fossils, many of which were less than 2mm in size. 'It was literally like panning for gold, except bird bones are our prize,' said Druckemiller. Wilson added that many of the bones were from embryos or hatchlings. At least one species of bird, she said, belonged to a now-extinct group called Ichthyornithes, and would have resembled a toothed seagull, while the researchers also found at least one member of another extinct group called Hesperornithes: foot-propelled diving birds with teeth. Many of the fossils came from toothless birds that may have resembled ducks. That, the team note, is significant because features such as a lack of teeth are a hallmark of Neornithes, the group that includes all living birds and their most recent common ancestor. It suggests the prehistoric birds nesting in the Arctic were close relatives of modern birds. Druckenmiller said that, like the Arctic today, the Prince Creek ecosystem of 73m years ago would have experienced about six months of continuous daylight in the summer, during which it would have been very green. As a result there would have been an abundance of food. However, the winter would have been chilly. 'While [winters were] not as harsh as today, year-round residents would have to endure freezing temperatures, occasional snowfall, and about four months of continuous winter darkness,' he said. Wilson said the newly discovered fossils showed the birds were breeding in the Arctic, but she said it was unclear if they spent the winter there, adding it was highly likely at least some of them were migratory. Steve Brusatte, a professor of palaeontology and evolution at the University of Edinburgh who was not involved in the work, said that while the fossils discovered by the team were 'absolutely minuscule', they told a huge story. 'These fossils show that birds were already integral parts of the these high-latitude communities many tens of millions of years ago, and thus that these communities are a long-term norm of Earth history, not a recent ecological innovation of modern times,' he said.
Washington Post
12-05-2025
- Climate
- Washington Post
In northernmost U.S. town, the sun won't set until Aug. 2
Think you've had a long day? Imagine living in Utqiagvik, Alaska. After rising on Saturday, the sun there will shine for 84 days, 11 hours, 4 minutes without setting. Meteorologists and astronomers call the lengthy bright stretch there 'polar day.' It's the opposite of 'polar night,' or the months of darkness that befall polar regions during winter. Between November and January, Utqiagvik (pronounced oot-kee-aag-vik) goes 64 days without witnessing a hint of direct daylight.
Forbes
09-05-2025
- Science
- Forbes
Get Ready For 50 Years Of Intense Northern Lights, Scientists Say
The Northern Lights may ramp up in intensity for the next 50 years as the sun potentially enters a new long-term phase of heightened activity, suggests a new study by solar scientists. The sun has a solar cycle lasting roughly 11 years, during which its magnetic intensity waxes and wanes. It's presently close to solar maximum, the peak of that cycle. There have been frequent sightings of the aurora far from the poles in the last year or two, the most severe of which was an extreme G5 geomagnetic storm on May 10-11, 2024, the most severe since 2003. Some researchers think it may have been the most powerful for hundreds of years. A paper published in Space Weather found that the sun may be on the cusp of entering a multi-decade period of intensity called the Centennial Gleissberg Cycle. A repeating longer-term pattern in solar activity, the CGC is a theoretical variation in the intensity of solar cycles over a century or so. It's possible that the last three solar cycles occurred during the CGC's minimum period, with the following three set to occur during its maximum. That could mean solar cycles over the next 50 years or so becoming more intense. The evidence for the CGC's current period is based on a correlation between the 11-year solar cycle and high-energy protons in Earth's inner radiation belt. Proton flux increases when solar activity decreases. Using two NOAA satellites, the scientists have seen a decline in proton flux during the recent uptick in solar activity, which correlates with the midpoint of the CGC. Until 2022, the proton flux had been increasing. Not all solar scientists agree with this theory. Scott McIntosh at space weather company Lynker Space and formerly of the National Center for Atmospheric Research at CU Boulder, told Live Science that it's 'too early' to make conclusions about the CGC and that the new paper may overestimate its effects. The scientists looked at the proton flux above the South Atlantic Anomaly in the South Atlantic Ocean, where Earth's magnetic shield is weakest. 'The protons are clearly decreasing in measurements we obtained from NOAA's Polar Operational Environmental Satellites,' lead author Kalvyn Adams, an astrophysics student at the University of Colorado, told Other evidence includes sunspot numbers — direct indicators of solar activity — now at their highest levels in over 20 years, signaling a more turbulent and energetic sun. The CGC could also explain why solar cycle 24 — which occurred between 2008 and 2019 — was the weakest for 100 years. While the paper focuses on proton flux, higher solar activity generally means more. and more intense, geomagnetic storms — an essential cause of spectacular displays of auroras. This new insight into the CGC could mean more opportunities for aurora sightings in mid-latitude regions, including in the U.S. and Europe. Even if the CGS theory is wrong, expect more aurora. As the sun's magnetic activity begins to wane from solar maximum, another landmark display of aurora could likely result. 'This period of solar decline is marked by a decreasing number of sunspots, but not necessarily by fewer impacts, even after the solar maximum,' said Lisa Upton, co-chair of NASA and NOAA's Solar Cycle 25 Prediction Panel, announcing the arrival of solar maximum in October 2024. The declining phase is notable for having extreme solar events. The Northern and South Lights (aurora borealis and australis) result from an interplay between the solar wind — a stream of charged particles constantly flowing from the sun — and Earth's magnetic field. When energetic particles reach Earth, they enter the polar regions, colliding with atoms and molecules in the upper atmosphere, exciting them and releasing energy as green and red lights.
